1. Field of the Invention
The present invention relates to a process and device for decomposing fibrous material.
In a particular example of the present invention, the device includes a drum having an inner wall, a first end and a second end, a displacer, having an outer wall, positioned inside the drum, and a processing channel formed between at least a portion of the outer wall and at least a portion of the inner wall. In a further example of the present invention, the process includes pouring fibrous material to be decomposed into the drum, moving the fibrous material from the first end to the second end, moving the inner wall relative to the outer wall in a peripheral direction of the drum, and mechanically processing the fibrous material in the processing channel.
2. Discussion of Background Information
Via a process similar in general to the above-noted type, contaminated, used paper is, in many cases, to be mixed with water and broken up. In the known processes, a decomposing drum, generally consisting of a cylinder in a horizontal position, which contains, for the most part, ring-shaped cover-plates on its front ends to avoid an undesirable escape of material, can be used in a first stage of the process. In the decomposing drum, water is added to the used paper to help break it up as is lifting, slipping, and falling or relative motions of the material segments to each other.
If sorting openings are provided in the jacket of the drum, the decomposed fibrous material can escape through them. Embodiments of such decomposition drums are illustrated and described, e.g., in German Patent Application No. DE-PS 32 10 503.
Processes for the treatment of used paper, which work with decomposing drums or similar devices discussed above, are known to have the advantage of an especially gentle decomposition, i.e., in regard to both sensitive types of fiber and undesired accompanying materials, which remain the ones to be sorted. However, the cost expenditure is a disadvantage in that this process can be used most favorably only with the kinds of used paper having a particularly simple decomposability, i.e., the used paper may not contain any parts of the kinds of paper which are difficult to decompose. The concepts of difficult and easy to decompose are well-known to the expert, such that newspaper paper is easily decomposed and "partial wet-strength," surface-treated, and "wet-strength" types of paper are difficult to decompose. The paper may also be discussed in terms of higher or lower decomposability. As a measure of decomposability, the specific work necessary during the decomposing process in the material decomposer to produce a slush is determined. For example, for newspaper paper, specific work amounts to about 15-20 kWh/t are necessary, while for liners or surface-treated paper, specific work amounts up to 80 kWh/t are necessary. For the reasons noted above, the process, in which decomposing drums, especially those that have proven reliable with so-called de-inking material, are used, the printed, sorted types of used paper are generally easy to decompose. However, even with this application, the decomposing drums have considerable dimensions.